Beverage preparation machines are becoming very popular whether at home or in offices. For instance, there are machines for the preparation of beverages such as coffee, tea, soup or other similar beverages, in which at least one ingredient of the desired beverage, for example ground coffee, is supplied within a capsule into a capsule extraction chamber of the machine.
The use of capsules, such as plastic and/or aluminium-based capsules for the preparation of beverages has many advantages. Capsules, in particular aluminium-based capsules, are hermetic or gas tight and thus can protect the beverage ingredient effectively during an extended period of time against the environment such as air, humidity or light, before use of the ingredient and thus prevent premature degradation of the ingredient. Furthermore, capsules of a beverage ingredient are easy to handle, hygienic, and their use involves less cleaning of the beverage preparation machine, in particular no significant part of the machine's extraction chamber comes into contact with the beverage ingredient contained in the capsule during the extraction process.
Capsules are usually inserted individually into the machine's extraction chamber, manually or automatically from a capsule stack. Hot or cold water is then passed through the capsule for brewing or otherwise extracting the ingredient(s) contained within the capsule and form the desired beverage. The prepared beverage is supplied via an outlet of the machine into a cup, mug or other receptacle to the user.
Used capsules may either be removed individually from the beverage preparation machine after each beverage preparation or they may be collected in a machine's used capsule collector for instance as mentioned in EP 1 731 065 (in the name of the present Applicant).
Typically, the capsule collector is located underneath the capsule chamber so that the capsules may fall by gravity into the collector upon extraction. In the latter case, the collector has to be emptied by the user when full. The collector may be a drawer-type removable receptacle located in a cavity of the beverage preparation machine typically under the extraction chamber. The used capsule collector may be slid in and out of the machine's housing.
A problem may arise with such capsule collectors, in particular in conjunction with rigid capsules, when used capsules accumulate in the receptacle form a heap of capsules whose top extends above the receptacle in such a manner to come into conflict with the housing when the receptacle is slid out of the machine's housing for emptying.
A solution to avoid the jamming of the collector by used capsules is to provide an optical level detector for measuring the level of capsules in the used capsule collector and inviting the user to empty the collector when the level of capsules comes close to the level of the machine's housing. Another solution involves counting the number of capsule extractions after emptying the collector and inviting the user to empty the collector after a predetermined number of capsules has been collected, an excess of which may possibly cause jamming.
A drawback with the level detector system involves the use of expensive electronic detectors, in particular optical detectors. Furthermore, since the accumulated capsules naturally form a heap in the receptacle a waste of space is usually also involved around this heap. A drawback of the capsule counting system lies in the fact that, in order to avoid jamming at all time, it is necessary to set a maximum number of collectible capsules in the receptacle that will often lead to a poor filling of the collector at the time when the user will be invited to re-empty the collector and to an even greater waste of space around the heap of collected capsules in the receptacle than with the above described level detector.
Hence, there is still a need to provide an inexpensive simple solution for avoiding jamming of a used capsule collector in a coffee machine while allowing optimal filling of the collector.